How adding abrasive waterjet increases CNC milling profitability
An ever growing number of fabricators and machine shops are gaining a competitive advantage by incorporating abrasive waterjets to their machining mix. What used to be known in the 80s as a rather obscure, albeit fascinating, cutting method has gone mainstream. In fact, abrasive waterjet machining is one of the fastest growing machining technologies in manufacturing, partly due to how well it complements a shop’s existing machine investments, such as CNC mills.
Smart businesses continuously look for purchases that will increase their productivity and reduce production costs. An abrasive waterjet can do exactly that by streamlining workflows and wasting less material.
Near net shaping with the waterjet saves time, tooling, and material expenses
Many manufacturers now cut the majority of a part on an abrasive waterjet and then move the part to a mill for finishing operations. Integrating this near net shape cutting into the process significantly reduces production time. An abrasive waterjet can handle large sheets of raw material and cut multiple blanks with very little setup and fixturing time. Abrasive waterjets cut material that’s difficult to machine on a CNC mill, such as Inconel, Hastelloy, and titanium, and there’s no need to change tooling to cut different types of material. OMAX waterjets are so easy to use that one operator can often run multiple machines simultaneously. A real world example is in this customer story about a metal fabricator with three OMAX machines. The waterjets are set up in a U-shape and one operator runs all three.
In addition to saving processing time, cutting near net shapes with a waterjet before milling can reduce tooling and material costs. Because the bulk of the cutting is done with the waterjet, there’s far less wear on expensive end mills, so they won’t need replacing as often. And purchasing large sheets of material that will fit on the waterjet table is often less expensive than buying smaller blocks of material that will fit on the mill.
Better material use reduces production costs
Waterjet machining is a cold process that doesn’t warp, harden or stress the material during cutting. The cut edge quality is very good and typically doesn’t require secondary operations to smooth the edge finish. Since there’s no heat-affected zone and a small kerf, waterjet cut parts can be tightly nested on a workpiece. With thermal cutting processes such as plasma and laser, the cut edges are melted, which means more space is required between nested parts, so more raw material is needed per part.
The by-product of waterjet cutting is a slug of material or a skeleton. That scrap material can often be used later for other, smaller parts. Or, it can be sold as scrap to a recycling service. The by-product of CNC milling is chips, which can’t be used as-is for additional parts. If sold to a recycling service, the chips are typically worth less than the same amount of scrap from a waterjet because extra processing is required to decontaminate the chips.
More capabilities means more business
Many shops find their abrasive waterjets bring some windfall advantages to the business. “It certainly has made our whole operation look differently at how we manufacture,” says Roger Hasler of Machintek, Corp. “Components we used to do on drills or mills we’ve moved to the waterjet because it cuts features more efficiently.” With a multi-axis A-Jet cutting head, an OMAX waterjet can easily cut beveled edges, angled sides and countersinks in materials that are difficult to machine on traditional CNC equipment. Some shops now use their waterjets to cut components to repair or enhance other machines on the manufacturing floor. The OMAX CAD/CAM software has tools to automatically generate part drawings for gears, sprockets, cams and other components that can be customized and cut from almost any material. This reduces machine downtime that might occur while waiting for an ordered part to arrive. For other shops, the waterjet addition has meant expanding into new markets because they’re now able to take in quick-turn prototype jobs at a healthy profit.